Fix attachment issues

Fixes https://github.com/PrivateBin/PrivateBin/issues/315
The attachment viewer is also used for storing to be uploaded
attachments, which caused some confusion in handling them.
I also tried to add some comments clarifying it as it seems to work.

Additionally I fixed the issue that you could submit an empty paste and
it was not rejected.

.gitignore

@@ -1,7 +1,9 @@
 # Ignore server files for safety
 .htaccess
 .htpasswd
-cfg/conf.php
+cfg/*
+!cfg/conf.sample.php
+!cfg/.htaccess
 
 # Ignore data/
 data/

js/privatebin.js

@@ -2005,6 +2005,19 @@ jQuery.PrivateBin = (function($, sjcl, Base64, RawDeflate) {
             $attachmentLink.off('click');
             $attachmentPreview.html('');
 
+            AttachmentViewer.removeAttachmentData();
+        };
+
+        /**
+         * removes the attachment data
+         *
+         * This removes the data, which would be uploaded otherwise.
+         *
+         * @name AttachmentViewer.removeAttachmentData
+         * @function
+         */
+        me.removeAttachmentData = function()
+        {
             file = undefined;
             attachmentData = undefined;
         };
@@ -2038,7 +2051,7 @@ jQuery.PrivateBin = (function($, sjcl, Base64, RawDeflate) {
         };
 
         /**
-         * checks if there is an attachment
+         * checks if there is an attachment displayed
          *
          * @name   AttachmentViewer.hasAttachment
          * @function
@@ -2053,7 +2066,9 @@ jQuery.PrivateBin = (function($, sjcl, Base64, RawDeflate) {
         };
 
         /**
-         * checks if there is attachment data available
+         * checks if there is attachment data (for preview!) available
+         *
+         * It returns true, when there is data that needs to be encrypted.
          *
          * @name   AttachmentViewer.hasAttachmentData
          * @function
@@ -2824,6 +2839,9 @@ jQuery.PrivateBin = (function($, sjcl, Base64, RawDeflate) {
                 $fileWrap.removeClass('hidden');
             }
 
+            // in any case, remove saved attachment data
+            AttachmentViewer.removeAttachmentData();
+
             // our up-to-date jQuery can handle it :)
             $fileWrap.find('input').val('');
 
@@ -3696,10 +3714,11 @@ jQuery.PrivateBin = (function($, sjcl, Base64, RawDeflate) {
             // get data
             var plainText = Editor.getText(),
                 format = PasteViewer.getFormat(),
+                // the methods may return different values if no files are attached (null, undefined or false)
                 files = TopNav.getFileList() || AttachmentViewer.getFile() || AttachmentViewer.hasAttachment();
 
             // do not send if there is no data
-            if (plainText.length === 0 && files === null) {
+            if (plainText.length === 0 && !files) {
                 // revert loading status…
                 Alert.hideLoading();
                 TopNav.showCreateButtons();

tpl/bootstrap.php

@@ -75,7 +75,7 @@ if ($MARKDOWN):
 <?php
 endif;
 ?>
-		<script type="text/javascript" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-5MEpLVeCKou7sL5U7X8uo5O0CG+1+aLGpN2O5Xvo9e31Ql7/7N8X03OCcwqBNEKv61IcSlxkCP9eLXZl8eMeBA==" crossorigin="anonymous"></script>
+		<script type="text/javascript" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-mJnXRlEN4mKPZWcq3Vwsql3hHa8X9EqsePjAGKadlbD4gF5m7MhwCreA9LQ/SOfoVGQQWG5xgTiuPEXLzs1D2g==" crossorigin="anonymous"></script>
 		<!--[if lt IE 10]>
 		<style type="text/css">body {padding-left:60px;padding-right:60px;} #ienotice {display:block;} #oldienotice {display:block;}</style>
 		<![endif]-->

tpl/page.php

@@ -54,7 +54,7 @@ if ($QRCODE):
 <?php
 endif;
 ?>
-		<script type="text/javascript" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-5MEpLVeCKou7sL5U7X8uo5O0CG+1+aLGpN2O5Xvo9e31Ql7/7N8X03OCcwqBNEKv61IcSlxkCP9eLXZl8eMeBA==" crossorigin="anonymous"></script>
+		<script type="text/javascript" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-mJnXRlEN4mKPZWcq3Vwsql3hHa8X9EqsePjAGKadlbD4gF5m7MhwCreA9LQ/SOfoVGQQWG5xgTiuPEXLzs1D2g==" crossorigin="anonymous"></script>
 		<!--[if lt IE 10]>
 		<style type="text/css">body {padding-left:60px;padding-right:60px;} #ienotice {display:block;} #oldienotice {display:block;}</style>
 		<![endif]-->